Earlier this year, NASA announced the first-ever medical evacuation in the International Space Station’s 25 years of continuous human occupation.Within days, the crew of four astronauts boarded their SpaceX Crew Dragon spacecraft, splashing down in the Pacific Ocean on January 15. They were immediately whisked away in a helicopter to the nearby Scripps Memorial Hospital La Jolla, near San Diego, leaving the press with plenty of glaring questions.Last month, 59-year-old retired US Air Force colonel and crew member Mike Fincke publicly identified himself as the one who had fallen ill and triggered the evacuation.Now he’s finally ready to expand on what actually happened — and by all accounts, it sounds like a terrifying experience for both him and his fellow crew members.As the Associated Press reports, Fincke said he suddenly was unable to speak for a period of about 20 minutes while having dinner. Fincke and his fellow crewmates had just ended preparations for a spacewalk, which had to be cancelled as the incident unfolded.“It was completely out of the blue,” he told the AP. “It was just amazingly quick.”After they saw he was distressed, his crewmates jumped into action and requested help from flight surgeons back at Houston HQ.“It was all hands on deck within just a matter of seconds,” he said.What exactly caused his momentary ability to speak remains a medical mystery. Doctors have ruled out choking or a heart attack.One particularly intriguing possibility remains: it may have had something to do with the fact that he had been five and a half months into his latest stint on board the space station, a prolonged period of being exposed to the microgravity of space.Scientists continue to study the health effects of space travel on the human body, from bone density loss to deteriorating vision. How an inability to speak could in any way fit into the broader body of research remains unclear at best.After returning to Earth, Fincke has since been put through a gauntlet of tests, but a singular cause for the crisis has yet to be identified.“I’ve been very lucky to be super healthy,” he told the AP. “So this was very surprising for everyone.”In total, Fincke has spent 549 days in space. Despite experiencing what must have been a harrowing moment, he’s still hoping to return, he told the AP.More on the incident: The Saga of NASA’s Space Station Evacuation Keeps Getting StrangerThe post NASA Astronaut Reveals Terrifying Medical Incident That Caused Evacuation from Space Station appeared first on Futurism.